1. Field of the Invention
This invention relates to protective headwear of the type designed to protect the head of the wearer by deflecting, distributing, or absorbing forces which would otherwise cause injury, and in particular to a helmet or hard hat illuminated by a plurality of light emitting diodes (LEDs).
2. Discussion of Related Art
The use of LEDs for illumination of protective headwear (including both helmets and hard hats) is known from a number of prior patents. However, while LEDs are relatively inexpensive in comparison with other types of lighting elements, such as electro-luminescent panels, conventional LED lighting arrangements present an number of problems in the context of protective headwear. These problems including difficulties in assembling the lighting arrangement to the headwear, making mass production at an acceptable cost impractical, and the potential for injuries caused by penetration of the LEDs into the head of the wearer during an impact. In addition, LEDs have a relatively narrow viewing angle in comparison with incandescent and electro-luminescent lighting elements, and thus are at present of limited utility for night time helmet applications where the goal is to make the wearer more visible to motorists and others.
U.S. Pat. No. 4,231,079, for example, discloses an illumination arrangement for a hard hat in which a plurality of LEDs are arranged in a single layer. The arrangement disclosed in this patent has a number of disadvantages common to all conventional lighting arrangements involving LEDs, including a relatively narrow viewing angle, limited display patterns, and relatively difficult assembly to the hard hat, particularly if area wide lighting is desired, such as might be the case if the lighting arrangement is used for advertising or promotional purposes. In addition, the LEDs present a serious risk of injury to the wearer of the hard hat because they could, during an impact, penetrate the head of the wearer, which could cause a terrible brain injury.
Another example of a prior art illuminated protective headwear arrangement, in this case a motorcycle helmet utilizing LEDs, is disclosed in U.S. Pat. No. 4,901,210. Like the arrangement described in the above-mentioned U.S. Pat. No. 4,231,079, the arrangement described in this patent has the visibility disadvantages of conventional LED arrangements and also has the disadvantage of utilizing a relatively bulky housing construction which is exposed to breakage during impacts against the helmet and therefore presents a potential injury hazard to the wearer, only partially mitigated by the fact that the illumination housing is placed at the rear of the helmet.
More generally, non-protective headwear illumination arrangements are also disclosed in a number of prior patents, including U.S. Pat. No. 5,111,366, which discloses an area light for headwear. The illumination arrangement described in this patent utilizes the optical properties of a plastic panel to achieve a desired effect, but while the problem of narrow viewing angle is overcome by providing the optical panel, the structure of the illumination is complex and costly to assemble, and the safety problem is not even considered since this patent is not directed to protective headwear, but rather to a soft cap.
Another prior disclosure of a lighting arrangement for headwear in general is found in U.S. Pat. No. 1,572,210. This patent also does not involve protective headwear, and the lighting arrangement described therein would in fact not be suitable for protective headwear because it involves placement of incandescent glass bulbs on a visor, and therefore a serious risk of injury to the face, head, and brain. In addition, the use of incandescent lighting has the disadvantage of requiring a relatively large power supply.
Similarly, U.S. Pat. No. 4,901,211 describes an illuminated visor structure using unspecified lighting means, but requiring a complicated housing structure which would be both impractical and hazardous to use in any type of headwear intended to serve a protective function.
Finally, British Patent Publication No. UK 0 166 534, and U.S. Pat. Nos. 5,327,587 and 5,426,792 describe lighting arrangements utilizing electro-luminescent lighting elements which, although possessing a number of advantages, are too expensive and use too much power at this time to be widely accepted by consumers in the type of protective headwear applications disclosed herein.